*sukkōną

Most likely from pre-Germanic *suḱnéh₂-, a zero-grade iterative to Proto-Indo-European *sewḱ- (‘to suck’). The verb(s) *sūkaną/*sūganą (‘to suck’) very likely represent a back-formation from the iterative, as the expected outcome from inheritance would be *seuhaną. Cognates include Latin sūcus (‘juice’), Latvian sùkt (‘to suck’), Proto-Slavic *sъsàti (idem) (idem). On the other hand, Latin sūgō (‘to suck’) and Old Irish súigid (idem) (idem) seem to point to a voiced stop, for Proto-Indo-European *sewg- or *sewgʰ-, which could just as well have given the Germanic iterative *sukk-. Contamination by onomatopoeia in at least some of these words is probable; compare the developments of Italian succhiare, ciucciare and Sicilian sucari.